A guy is walking down the road and he sees a sign in a window "dog for sale". As he is looking for a dog to keep him company he opens the gate and walks up to the front door and pushes the buzzer.

With that a gruff voice from behind says "they ain't in". Looking round all he can see is this dog, so he says "who said that". The dog says "I did".

Very surprised the guy says "so you can talk?". The dog says "Yep. I used to work for the CIA as their most prized asset, sitting in on meetings and so on because no-one would ever guess that a dog was able to decipher what was being said".

"And after doing that for 8 years I spent another 3 years working in airports, wandering around suspicious characters and nailing those who were discussing hijacking aircraft. But I gave that up 'cos I was getting a bit too old and wanted to settle down".

The gate opened right then as the owner arrived and the guy asked how much he wanted for the dog "10 bucks mate".

"Wow! That's cheap - I'll take him. But why are you selling him so cheap?".

"The dog's a liar - he hasn't done any of those things he told you about".